Switching device



Dec. 29, 1925.

O. F. FORSBERG SWITCHING DEVICE Filed July 2, 1921 2 Sheets-Sheet 1 v fig.

narici-l: u |45/ Dec 29, 1925 1,567,253

Q. F. F'QRSBERG SWITCHING DEVICE Patented Dec. 29, 1925.

UNITED STATES PATENT OFFCEL OSCAR F. FORSBERG, OF YONKERS, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

sWITcHING DEVICE.

Application filed July 2,

To all whom it may concern:

Be it known that I, OSCAR F. Fonsnnc, a citizen of the United States, residing at Yonkers, in the county of Westchester, State of New York, have invented certain new and useful Improvements in Switching Devices, of which the following is a full, clear, concise, and exact description.

This invention relates in. general to switching devices and more particularly to such devices for use in connection with telephone or signaling systems in which circuit conditions require simultaneous closing of a large number of electrical circuits. A switch of this type is particularly suited for use as a line finder or district finder in automatic telephone systems, but its operation is such that it may be used effectively in various kinds of circuits where the conditions require the simultaneous closing of a large number of contacts.

It is the principal object of the present invention to provide a multiple type of switch which is cheap to manufacture and one in which the maintenance cost in serv* ice will be low. Another object of the invention is to provide a structure built up in unit construction so that the parts may be readily replaced without interfering with the service for any considerable length of time.

To accomplish these objects the invention provides a multiple contact relay in which the Contact springs or wires are caused to make Contact directly with contact wires which are common to the various units of ,the structure, and which are preferably arranged in the form of a. wire grid in operative relation to the individual contact wires, means being provided for insuring a wiping contact between the contact members as they are brought in engagement.

These and other features of the inven- 1 tion may be more clearly understood by reference to the accompanying drawing, in which Fig. 1 is a front elevation of a relay embodying the features of this invention; Fig. 2 is a sectional view taken along the line A2 2 of Fig. 1, showing the relation ofthe individual contact wires to the wire grid; Fig. 3 1s a perspective view partly in cross-section, showing more clearly the structure of the device andthe manner 1n which `the various parts are coordinated;

1921. serial No. 482,106.

Fig. 4 is a view of an individual camming plate; Fig. 5 shows the manner in which the contact wires are imbedded in the insulating strip; Fig. 6 is a view of the cirn cuit-controlling springs; Fig. 7 shows the electromagnet armature; Fig. 8 shows more clearly the wiping Contact or shearing effect present when using a woven wire grid; and F ig. 9 is an enlarged view showing the manner in which the wiping contact is brought about by means of the camming plate.

Referring more particularly to Fig. 1, there is disclosed a relay structure comprising two independent sections each -consisting of sixteen sets of twenty-live contact wires, adapted to engage with the corresponding contact wire multiple. This structure comprises an upper angle mounting plate 10 and lower angle mounting plate 11, which are rigidly held together by means of side plates 12, 12, which are riveted or otherwise fastened thereto. Located upon the front side of plates 10 and 11 and secured thereto by means of the screws 13, 18 are the grids, the construction of which is clearly shown in Figs. 1, 2 and 3. Each grid -comprises a plurality of spaced strips 14, 14 of insulating material, such for eX- ample as phenol fiber or hard rubber, the ends of which are secured between clamping plates 15, 15 and 16, 16 which are clamped together by means of screws 17, 17. The insulating strips 14, 14 which are provided with uniformly spaced notches, as shown, serve as the woof of the grid, and the contact wires 18, 18 of phosphor bronze or similar material, which serve as the warp of the grid, are woven, as shown, in notches of the individual strips. U

Securely mounted to the back of mount; ing plates 10 and 11 are the electromagnets 20, 20, these mounting plates also serving as return pole pieces for the electromagnets. Also secured to the top and bottom of plates 10 and 11, by means of screws 19, are the plates 21 which are provided at the rear with openings 22, 22 through which extend the L-shaped armatures 23 of the electromagnets 20. In the front ends of these plates, and positioned in alignment with the center between openings 22, 22 are the extensions 24, 24, which in one plate are staggered with respect to the similar extensions of the other plate. The free ends of the armatures 23 are formed, as shown,-and each is provided with a transverse slot 25 having a perforation 26 centrally located therein.

Suspended between .each armature 23 and the extension 24 which is in vertical alignment therewith, is a camming plate 27 of insulating material, such as phenol fiber. This plate is provided at one end with a supporting member 28, which is threaded to passl through the perforation 26 and is provided with an adjusting nut 29 having a knife-edge portion adapted to cooperate with the slot 25 in the armature and prevent rotation. The other end of this plate is provided with a helical spring 30 which is adapted to hook over the end of extension 24. Each camming plate 27 is provided with a series of alternate slots 31, 31, extending in opposite directions with respect to the vert-ical plane of the plate.

Secured to the side. plates 12, 12 are the horizontal mounting plates 32, 32, to which are securely riveted spring plates of phosplior bronze or similar material, these plates being provided with T-sliapedv extensions 33, 33. The extensions 33 serve to hold in position a contact unit comprising an insulating bai' 34, in which are secured the individual contact wires 35, 35. These wires which are preferably providedV with a crimped portionv which is molded directly in to thebar 34, as shown in Fig. 5,`are provided with bent-back portions or hooks 36 lto facilitate the soldering of connections. The free ends of the contact wires- 3535 are adapted to thread through the slots 31 in camming bar 27 and lie between theI insulating strips 14, 14 and between adjacent wires 18 18.

flhe contact wires are preferably securedr to bar 34 in such a way'that their normal tendency is to bear against their respective grid Wires with the desired contact pressure. In the normal or unoperated position of the camming plate, the contact wires are re- I strained from making contact, but upon operation of the camming plate, they are permitted to move into engagement with the grid wires. Such an arrangement makes it possible during manufacture to position the i wires 35 at such an angle to the bar 34 that upon operation, the desired lcontact pressure is' obtained without any further adjustment of the individual contact wires. Moreover, with such an arrangement, the camming plate is suspended freely in position in a balanced condition, the pull of the helical:

spring 30 being counterbalanced by the come bined tension of' the contact springs acting against the camming plate', thus maintaining the camming plate in position without any guiding means which would" add friction to the structure.

The arn'iat-ures 23, as shown, are adapted4 nuts to be positioned so as to pivot on the outer rear edge of plates 10 and 1l, and arerheld in position by means of the screws 38 and 39, cooperating with the formed plate 40. This plate is provided at. one end with a right-angled extension 41 adapted to fit within the slots 42 in plate 21, and at its other end is mounted a spring pile comprising Contact springs 43, 43 between which are provided insulating spacers 44, of phenol fiber or similar material, the. entire assembly being held together by means of clamping plate 45 and screws 46. The armature is also provided with an insulating stud 47, which engages the free end of one vof the contact springs 43, and causes opening and closing of the contacts upon movement of the. armature. The air-gap adjustment of the armature is obtained by means of screw 48, which is threaded into the armature and adapted to bear against the clampingA plates 10` or 11. This screw is provided with a lock-nut 49 to prevent any change of adjustment during service. A proper adjustment lof the camming bar, with respect to the grid, is obtained by means of the adjusting nut 29, and the knife-edged portion of this nut not only providesa locking feature but alsoV allows the plate to ride freely upon'the armature without anybinding. l

In operation the energization of one of' the electromagnetsy causes its armature to be attracted, thus resulting in a movement of the corresponding camming plate 27 against the tension of the retractible spring 30. The wires 357thus move under their own tension into engagement with coopera'tingwires 18 of the grid, and since tlie slots 3l are oblique to the direction ofv movement, the ends of wires 35 are displaced horizontally, thus causing a wiping or rubbing action on the wires 18, as clearly shown in F ig. 9 of the drawing in which the position of wires 35 under normal conditions is shown in full lines, and the corresponding position when operatedis shown by dotted lines, the arrows representing the direction and also the distance of the horizontal movement of the wires 35. It will be noted that when the camming plate 27` is drawnupward by its operating magnet, the upper wire 35 moves vertically until it engages with the upper wire 18, and the direction ofthe slot 31 is such that'for the balance of the movement of plate 27,- the wire 35 is held in contact with 'the wire l18 and moves horizontally to the right. In the case of the lower wire 18 illustrated in this figure, the wire first moves into engagement with 'the lower wire 18 and' the direction of the corresponding slot in plate 27 is such as to cause the wire 18 to then move horizontally to the left. By thus employing slots running in opposite directions, it is possible to entirely eliminate the side thrust which would otherwise be present and would be ofA considerable magnitude in case of a relay having a large number of contact wires, each wire being under suicient contact pressure to insure a satisfactory contact. Furthermore, since the grid wires are woven, there is also provided a shearing action which results in a wiping along the wires 35, as will be seen more clearly by referring particularly to Fig. 8.A 'l

IVith the arrangement of the parts as shown, when the wire 35 moves horizontally to the right to take up the position shown by the dotted lines, its point of contact has varied a distance somewhat greater than the thickness of the insulating strips 14, thus f causing a rubbing action on the wire 35 as well as on the wire 18. This combined shearing and wiping effect serves very eiciently to insure a low resistance contact between the individual contact wires and the grid wires.

The grids are made up as a unit and are held in position by means of screws 13, 13. Thus, in case of injury to the grid or any defects which may become apparent, it is possible to very quickly and very easily remove the grid and replace it with another. The wire contact springs 35 are also ar ranged so as to be easily replaced since by spreading apart the spring extensions 33, 3 at the top and bottom, the entire unit may be quickly removed and another substituted. 'Ihe camming plates are also so arranged as to be easily interchangeable and are freely suspended between the grid and the mounting plates, the self-locking adjustment described above being provided for obtaining the proper position of the plates with respect to the grids. By staggering electromagnets, that is, having the operating magnet for adjacent bars positioned alternately at the top and bottom of the device, a structure is provided which is very compact.

What is claimed is:

1. In a switching device, a set of passive contact members comprising bare wires arranged in woven grid formation, a set o f active bare wire contact members coordinately `disposed to other said set, and means for causing the active wires to move in one operation in two directions at right angles to each other, the initial motion of the active wires causing them to engage the pasi sive wires, the continued motion of the active wires causing them tovary the point of engagement with said passive wires.

2. In a switching device a grid unit comprising a plurality of parallel conductors insulated from each other, a plurality of other conductors fixed at one end and substantially perpendicular to said grid and having their free ends extending between the conductors thereof, and means for moving said other conductors into engagement with the conductors of said grid and providing a wiping action on each of said con-- ductors.

' 3. In a switching device a grid unit comprising a. plurality of bare wires supported on notched insulating strips, a plurality of conducting' springs having their free ends extending between adjacent wires of said grid, a camming plate adapted to permit said conducting springs to move siinultaneously into engagement with the wires of the grid, and means for causing the operation of the camming plate.

4. In a switching device a grid unit comp-rising a plurality of bare Wires supported on insulating strips, a plurality of conduct-- ing' springs having their free ends extending between adjacent wires of said grid, a camming plate provided with a plurality of oblique slots through which the free ends of said conducting springs extend, and an electromagnet for 'causing the movement of said plate whereby the conducting springs are moved with a wiping action into engage ment with the wires of said grid.

5. In a switching device a grid unit comprising a plurality of bare wires supported on notched insulating strips, a plurality of conducting springs having their free ends extending between adjacent wires of said grid, a camming plate provided with a plurality of oblique slots through which the free ends of said conducting springs extend, adjacent slots being formed in said plate in opposite directions substantially as shown to neutralize side thrust, and an elec-- t-romagnet for causing the movement of said plate whereby the conducting springs are moved with a wiping action into engagement with the wires of said grid.

6. In a switching device a mounting frame, a woven grid unit iixedly mounted on said frame, a plurality of sets of resilient contact members interchangeably mounted on said frame each of said sets comprising a stationary insulating bar having a plurality of conducting springs rigidly secured therein, and means for flexing said contact members.

7 In aswitching device a mounting frame, a grid unit mounted on said frame, a plurality of sets of contact members interchangeably mounted on said frame each of said sets comprising an insulating bar having a plurality of conducting l springs rigidly secured therein, and spring means for locking said bars in place. v

v8. In a switching device a grid unit comprising a plurality of parallel conductors insulated from each other, a camming plate provided with a plurality of slots mounted` adjacent said grid unit, a plurality of conducting wires having theirv free ends extending through the slots in said camming plate and between the adjacent wires of the grid unit, and means for moving said camming plate to cause said wires to move into engagement with the wires of the grid.

9. In'a switching device a grid unit comprising a plurality of parallel conductors insulated from each other, a camming plate provided with a plurality of slots mounted adjacent said grid unit, a plurality of conducting wires having their free ends extending through the slots in said camming` plate,l

and between the adjacent wires of the grid unit, an electi'omagnet for causing; the movement of said camming plate and adjustable means :tor changing the normal posi- 1U tion of said camming plate with respect to the grid.

10.` In a switching device a grid unit comprising `a plurality of parallel conductors insulated from each othei',.a camming plate provided with a,V plurality of slots mounted adjacent-'said grid unit, an electromagiiet for causing the movement of said camming plate, and adjustable self-locking means for changing the normal position of said camming plate with respect to the grid.

11. In a switching device a mounting frame, a grid unit on said frame, said unit. comprising a plurality of conductors insulated i'rom each other, a plurality of conducting springs mounted on said frame perpendicular to the plane of the grid unit, and means for moving said springs into engagement with the grid conductors.

12. In a switching-device a mounting 85 frame, a grid unit removably mounted on said Jframe, said grid comprising a plurality of parallel conductors insulated from each other, a. plurality of conducting springs mounted on said frame perpendic- 40 ular to the plane of the grid unit, and

means for moving said springs into engagement with the grid conductors.

13. In a switching device a mounting frame, a grid unit removably mounted on said frame, said unit comprising a plurality of conductors insulated from each other, a plurality of conducting springs mounted on said frame perpendicular to the plane of the grid unit and having their free ends extending between adjacent conductors, and means for moving said springs into engagement with the grid conductors.

14. In a switching device a mounting frame, a woven wire grid removably mounted on said frame, said grid unit comprising a plurality of parallel wire yconductors insulated from eachv other, a plurality of conducting springs mounted-,on said frame perpendicular to the plane of the grid unit, and means for moving said springs into engage.- ment with the grid conductors. i

l5. In a switching device a mounting frame, a removable grid unit mounted. on said frame, said unit comprising a fabric of bare wires forming the warp and rigid insulating strips forming the Woof, a plurality of conducting springs mounted on saidframe perpendicular to the plane of the grid unit, and. means for causing said springs to engage the wires of the grid.l

- 16. In a switching device, a mounting frame, a grid unit replaceably mounted on the front-of said frame, a plurality of sets of contact members mounted within said frame, each set of contact members compris ing a plurality of contact ,wires having their free ends perpendicular to the plane of said grid, acamming plate having oblique slots therein through which the vfree ends of said contact wires extend, and an individual electroinagnet for each of said camming plates mounted within said frame and utilizingthe frame as a returnpole piece. l

17. In` a switching device, a woven wire grid, a set of active wires with their ends extending through the grid, an operating member normally holding the active wires'f under tension and out of engagement with the grid wires, and means for actuating. said member to effect engagement between the active wires and the grid wires.` 1

18. In a switching device a set of con-v tact members, a second set of bare contact members normally tensioned tol engagey saidy i'st set of contact members, means for normally maintaining said contactmembers out of engagement, said means upon operation cooperating with the tension of the bare wire conductors to permit them to move into engagement with the set of contact mem- 20. In a switching device, a grid consist-A ing of conductors Woven with insulating strips, a set' of activev conductors mounted with their free ends extending into cooper-l ative relation with said grid conductors,

and means for flexing the active conductors to move them into engagement with said grid conductors.

21. In a switching device, a `woven' wire grid, a set of active wires mounted` with their free ends extending through .the gridto cooperate with said woven wires, and

means for causing the active wires to move into contact with the grid wires.

22. In a switching device, a woven wire grid made up of passive wires and 'insulatf ing strips, a plurality of active wires having,

their ends extending through said grid to cooperate with said passive wires, an operating member having slots in which the active wires are held under tension and out of contact with the passive wires, and means for moving said member to release the active wires into engagement with the passive wires of the grid, said slots causing the active wires to wipe over the passive wires.

23. In a switching device, a woven wire grid, a plurality of active contact wires mounted with their free ends projecting through said grid, an operating member having diagonal slots through which the active wires extend, said active wires being held normally by said member under tension and disengaged from the grid wires, and means Jfor moving the operating member, the initial movement of said member releasing the active wires into contact with the grid wires, the continued movement of the operating member causing the active wires through the action of said slots to wipe over the grid wires.

24. In a switching device, a woven wire grid, a plurality of sets of active contact wires mounted with their free ends extending through the grid to cooperate with said woven Wires, and means for causing any set of active wires to move into contact with the woven wires of the grid.

25. In a switching device, a woven wire grid, a plurality of sets oi' active contact wires mounted with their free ends normally extending through and in operative relation with the grid wires, and individual electromagnets for causing the operation independently of any set ci active wires to engage the grid wires with a wiping action.

26. In a switching device, a contact grid comprising insulating elements and a plurality of curved conductors supported by said elements, active conductors normally extending through said grid into cooperativ-e relation with the grid conductors, and means for causing the active conductors to move into contact with said grid conducto-rs, the curvature of the grid conductors causing a wiping action between them and the active conductors.

27. In a switching device, a plurality of insulating elements, passive conductors woven in and out with the insulating elements, active conductors mounted with their :tree ends exten-ding into cooperative relation with the passive conductors, and means for causing the active conductors to engage and wipe over a portion of the length of the passive conductors, the disposition of said passive conductors due to weaving causing a wiping action over a portion of the length of the active conductors.

28. A switch comprising movable contacts, iixed contacts, and means for moving said first contacts in a plane at right angles to the plane of said fixed contacts and along the length thereof, whereby a wiping engagement is eiected between said contacts.

In witness whereof, I hereunto subscribe my name this 28th day of June A. D., 1921.

OSCAR F. FORSBERG. 

